Wrap around side impact airbag systems and methods

ABSTRACT

An airbag assembly may include an inflatable curtain airbag with a stowed configuration and a deployed configuration. The inflatable curtain may have a first chamber and a second chamber that inflates forward of the first chamber. The second chamber may be separated from the first chamber by a non-inflating region. The non-inflating region may have a width selected such that in-plane bending of the inflatable curtain occurs during deployment. The in-plane bending may position the second chamber lower than the first chamber such that the second chamber overlaps a significant portion of a door adjacent to the inflatable curtain. Forward and rearward portions of the non-inflating region may be attached together to form a fold that decreases the width of the non-inflating region, thereby enhancing the in-plane bending. The second chamber may also bend out-of-plane relative to the first chamber to help provide protection in small overlap collision situations.

TECHNICAL FIELD

The present invention relates to automotive safety. More specifically,the present invention relates to an inflatable airbag curtain and methodthat provide protection in small overlap and oblique frontal collisionsand side collision situations.

BACKGROUND

Inflatable safety restraint devices, or airbags, are mandatory on mostnew vehicles. Airbags are typically installed as part of a system withan airbag module in the steering wheel on the driver's side of car andin the dashboard on the passenger side of a car. In the event of anaccident, a sensor within the vehicle measures abnormal deceleration andtriggers the ignition of a charge contained within an inflator.Expanding gases from the charge travel through conduits and fill theairbags, which immediately inflate in front of the driver and passengerto protect them from harmful impact with the interior of the car.Typically, airbags are concealed within the vehicle trim to be invisibleduring normal vehicle operation.

Airbag systems have also been developed in response to the need forsimilar protection from lateral impacts between a passenger and the sideof a vehicle's interior. This might occur when another vehicle collideswith the side of the car, or in a rollover situation where the side ofcar is repeatedly impacting the ground. Side impact airbags are oftencalled “inflatable curtains.” Many inflatable curtains are stowed alongthe corner where the vehicle roof meets the side windows and pillars.These inflatable curtains may be stowed behind the headliner trim at theedge of the headliner, which is the fabric covering the roof of thevehicle.

Recent safety standards issued by various governments require morecomprehensive protection in the event of a side or frontal collision.Additionally, there is an ongoing need to provide airbag systems thatare economical to manufacture and install, avoid interference with theability of the automaker to position various features on the vehicleinterior, and can be expected to deploy reliably. The passengers of avehicle may be at any of a wide variety of positions within the vehicleat the time of deployment, so it is desirable to provide airbag systemsthat protect against impact over the broadest possible range of occupantlocations.

It has been observed that some existing inflatable curtain designs donot provide adequate protection in the event of certain collisionevents, such as rollover collisions. In a rollover collision, theposition and trajectory of vehicle occupants is difficult to predict.Accordingly, known inflatable curtains designed to protect against apure lateral impact may not be in the proper position to provide theprotection that is most needed. The result may be injuries from impactwith interior vehicle surfaces and/or ejection from the vehicle, despitedeployment of the airbag systems.

Additionally, one safety need that has recently become apparent is theneed for enhanced protection in the event of “small overlap” and“oblique” collisions. A small overlap collision is a frontal collisionin which the impact occurs on a relatively narrow portion on the left orright side of the front of the vehicle. An oblique collision is afrontal collision in which the impact occurs at an angle from head-onand on a relatively narrow portion on the left or right side of thefront of the vehicle. Such collisions may lead to greater deformation ofthe vehicle structure on the side on which the impact occurs. Also, suchcollisions tend to cause the center of the vehicle to rotate away fromthe line of travel which can cause the vehicle occupant to move in aforward outboard trajectory. Additionally, existing airbag systems maynot sufficiently protect against small overlap and oblique collisionsbecause the trajectory of the occupants within the vehicle may bedifferent from those for which the airbag systems are designed toprovide protection. For example, in a vehicle with a driver's sideairbag and an inflatable curtain airbag, the driver's head may moveforward with a vector that has forward and lateral components so thatthe head tends to move between the deployed driver's side airbag and thedeployed inflatable curtain airbag. This may cause the driver's head tostrike the A-pillar or the instrument panel of the vehicle in spite ofthe deployment of the airbag systems.

Additionally, it is desirable to reduce the cost, complexity, andmanufacturing time of airbags. Simpler, cheaper airbag systems may notonly save consumers money, but may also extend the availability ofairbag systems to vehicle occupants who may otherwise be under-protectedin the event of an automotive collision.

SUMMARY OF THE INVENTION

The various systems and methods of the present invention have beendeveloped in response to the present state of the art, and inparticular, in response to the problems and needs in the art that havenot yet been fully solved by currently available airbag systems andmethods. Thus, it is advantageous to provide airbag systems and methodsthat provide reliable protection for vehicle occupants in a wide varietyof collision situations. Further, it is advantageous to minimizemanufacturing and installation costs. The present invention may haveother benefits that are not specifically set forth herein.

To achieve the foregoing, and in accordance with the invention asembodied and broadly described herein, an airbag assembly may bedisposed in a vehicle to shield a vehicle occupant from impacting atleast one lateral surface of the vehicle. The airbag assembly mayinclude an inflatable curtain airbag having a stowed configurationproximate the roof of the vehicle and a deployed configuration intowhich the inflatable curtain airbag deploys downward between the vehicleoccupant and the at least one lateral surface of the vehicle. Theinflatable curtain airbag may have an inboard fabric layer and anoutboard fabric layer that are secured together at a peripheral junctureto define, interior to the peripheral juncture, a first chamber, asecond chamber in fluid communication with the first chamber, and anon-inflating region extending from the peripheral juncture to at leastpartially separate the first chamber from the second chamber. Thenon-inflating region may have a width selected to permit in-planebending of the inflatable curtain airbag in the deployed configuration.

The non-inflating region may have a generally vertical portion thatextends upward from a bottom edge of the peripheral juncture between thefirst chamber and the second chamber. In the deployed configuration, thein-plane bending of the inflatable curtain airbag may cause the secondchamber to be angled downward relative to the first chamber. Thenon-inflating region may further have a generally horizontal portionthat extends forward of the generally vertical portion to divide thesecond chamber into an upper segment and a lower segment. In thedeployed configuration, the second chamber may inflate inboard of awindow, and the lower segment may extend significantly lower than abottom of the window and lower than the first chamber.

The second chamber may further have a forward segment. The uppersegment, the forward segment, and the lower segment may cooperate todefine a single non-branching passageway that conducts inflation gasfrom the first chamber to the upper segment, from the upper segment tothe forward segment, and from the forward segment to the lower segment.In the deployed configuration, the lower segment may be angled such thaton the lower segment, an exterior surface of the inboard fabric layerfaces upward.

The width of the non-inflating region may be between 7 mm and 20 mm. Inthe deployed configuration, the second chamber may be positioned betweenan occupant zone that would ordinarily be occupied by the vehicleoccupant's head and at least one of an A-pillar of the vehicle and aportion of an instrument panel of the vehicle.

The airbag assembly may further have a tether with a first end securableto the second chamber and a second end securable to the vehicle to urgethe inflatable curtain airbag to fold out-of-plane, in the deployedconfiguration, at the non-inflating region to position the secondchamber inboard of the first chamber. The airbag assembly may also havean attachment feature that attaches a forward portion of thenon-inflating region to a rearward portion of the non-inflating regionsuch that a compaction feature is defined between the forward portionand the rearward portion to compress the width of the non-inflatingregion. The compaction feature may be selected from the group consistingof a fold and a cut. The attachment feature may be stitching applied tothe forward portion and the rearward portion.

According to one method for manufacturing an airbag assembly forprotecting a vehicle occupant from impact against a lateral surface ofthe vehicle, the method my include providing an inboard fabric layer andan outboard fabric layer, securing the inboard fabric layer to theoutboard fabric layer at a peripheral juncture to form an inflatableairbag curtain, and compacting the inflatable curtain airbag into agenerally elongated shape. The generally elongated shape may facilitatesecurement of the inflatable curtain airbag proximate a roof of thevehicle such that, in response to introduction of inflation gas into theinflatable curtain airbag, the inflatable curtain airbag expandsdownward into a deployed configuration to be positioned between thevehicle occupant and the lateral surface of the vehicle. Securing theinboard fabric layer to the outboard fabric layer may include defining,interior to the peripheral juncture, a first chamber, a second chamberin fluid communication with the first chamber, and a non-inflatingregion extending from the peripheral juncture to at least partiallyseparate the first chamber from the second chamber. The non-inflatingregion may have a width selected such that, during deployment, theinflatable curtain airbag folds in-plane.

Defining the non-inflating region may include forming a generallyvertical portion that extends upward from a bottom edge of theperipheral juncture between the first chamber and the second chamber.The width may further be selected such that, in the deployedconfiguration, the in-plane bending of the inflatable curtain airbagcauses the second chamber to be angled downward relative to the firstchamber. The second chamber may inflate inboard of a window, and thesecond chamber may extend significantly lower than a bottom of thewindow.

Defining the non-inflating region may further include forming agenerally horizontal portion that extends forward of the generallyvertical portion to divide the second chamber into an upper segment, aforward segment, and a lower segment. These segments may cooperate todefine a single non-branching passageway that conducts the inflation gasfrom the first chamber to the upper segment, from the upper segment tothe forward segment, and from the forward segment to the lower segment.Compacting the inflatable curtain airbag into the generally elongatedshape may include facilitating securement of the inflatable curtainairbag at a position selected such that, in the deployed configuration,the second chamber is positioned between an occupant zone that wouldordinarily be occupied by the vehicle occupant's head and at least oneof an A-pillar of the vehicle and a portion of an instrument panel ofthe vehicle.

The method may further include attaching a forward portion of thenon-inflating region to a rearward portion of the non-inflating regionwith an attachment feature such that a fold is defined between theforward portion and the rearward portion to compress the width of thenon-inflating region. The attachment feature may include stitching.Attaching the forward portion of the non-inflating region to therearward portion of the non-inflating region may include stitching theforward portion to the rearward portion.

According to one embodiment of the invention, an airbag assembly may beprovided for disposition proximate a roof of a vehicle to shield avehicle occupant from impacting at least one lateral surface of thevehicle. The airbag assembly may include an inflatable curtain airbaghaving a stowed configuration proximate the roof of the vehicle and adeployed configuration into which the inflatable curtain airbag deploysdownward between the vehicle occupant and the at least one lateralsurface of the vehicle. The inflatable curtain airbag may have aninboard fabric layer and an outboard fabric layer that are securedtogether at a peripheral juncture to define, interior to the peripheraljuncture, a first chamber, and a second chamber in fluid communicationwith the first chamber. The second chamber may have a singlenon-branching passageway that includes an upper segment through whichinflation gas enters the second chamber from the first chamber, and alower segment below the upper segment and adjacent to a bottom edge ofthe peripheral juncture. The lower segment may direct the inflation gasback toward the first chamber.

The inboard fabric layer and the outboard fabric layer may further besecured together to define a non-inflating region with a generallyvertical portion that extends upward from a bottom edge of theperipheral juncture to at least partially separate the first chamberfrom the second chamber, and a generally horizontal portion thatseparates the upper segment from the lower segment. The singleunbranching pathway may further have a forward segment positioned toconvey the inflation gas downward from the upper segment to the lowersegment.

The inboard fabric layer and the outboard fabric layer may further besecured together to define a non-inflating region with a generallyvertical portion that extends upward from a bottom edge of theperipheral juncture to at least partially separate the first chamberfrom the second chamber, and a generally horizontal portion thatseparates the upper segment from the lower segment. The non-inflatingregion may have a width selected to permit in-plane bending of theinflatable curtain airbag in the deployed configuration. The in-planebending of the inflatable curtain airbag may cause the second chamber tobe angled downward relative to the first chamber such that the secondchamber inflates inboard of a window. The lower segment may extendsignificantly lower than a bottom of the window.

The inboard fabric layer and the outboard fabric layer may further besecured together to define a non-inflating region with a generallyvertical portion that extends upward from a bottom edge of theperipheral juncture to at least partially separate the first chamberfrom the second chamber, and a generally horizontal portion thatseparates the upper segment from the lower segment. The airbag assemblymay further have an attachment feature that attaches a forward portionof the non-inflating region to a rearward portion of the non-inflatingregion such that a fold is defined between the forward portion and therearward portion to reduce a width of the non-inflating region.

These and other features and advantages of the present invention willbecome more fully apparent from the following description and appendedclaims, or may be learned by the practice of the invention as set forthhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention will become more fully apparentfrom the following description and appended claims, taken in conjunctionwith the accompanying drawings. Understanding that these drawings depictonly exemplary embodiments and are, therefore, not to be consideredlimiting of the invention's scope, the exemplary embodiments of theinvention will be described with additional specificity and detailthrough use of the accompanying drawings in which:

FIG. 1 is a side elevation view of an airbag assembly in a stowedconfiguration within a vehicle according to one exemplary embodiment ofthe invention;

FIG. 2 is a side elevation view of the airbag assembly of FIG. 1,wherein the inflatable curtain airbag is in a deployed configuration;

FIG. 3 is a top view of the airbag assembly of FIG. 1, wherein theinflatable curtain airbag is in the deployed configuration;

FIG. 4 is a side elevation view of an airbag assembly in a stowedconfiguration within a vehicle according to one exemplary alternativeembodiment of the invention;

FIG. 5 is a side elevation view of the airbag assembly of FIG. 4,wherein the inflatable curtain airbag is in a deployed configuration;

FIG. 6 is a side elevation view of the forward portion of the inflatablecurtain airbag of the airbag assembly of FIG. 4, prior to compaction ofthe inflatable curtain airbag into the stowed configuration;

FIG. 7 is a top view of the airbag assembly of FIG. 4, wherein theinflatable curtain airbag is in the deployed configuration;

FIG. 8 is a side elevation view of the forward portion of an inflatablecurtain airbag of an airbag assembly according to another alternativeembodiment of the invention, prior to compaction of the inflatablecurtain airbag into the stowed configuration;

FIG. 9 is a side elevation view of the forward portion of an inflatablecurtain airbag of an airbag assembly according to another alternativeembodiment of the invention, prior to compaction of the inflatablecurtain airbag into the stowed configuration;

FIG. 10A is an oblique section view of the non-inflating region of theinflatable curtain airbag of FIG. 9 after attachment of the forwardportion of the non-inflating region to the rearward portion of thenon-inflating region;

FIG. 10B is an oblique section view of the non-inflating region of aninflatable curtain airbag according to another alternative embodiment ofthe invention after attachment of the forward portion of thenon-inflating region to the rearward portion of the non-inflatingregion;

FIG. 11 is a side elevation view of the forward portion of an inflatablecurtain airbag according to another alternative embodiment of theinvention, in the deployed configuration;

FIG. 12 is an oblique section view taken through the plane marked 12-12of the inflatable curtain airbag of FIG. 11 in the deployedconfiguration; and

FIG. 13 is an oblique section view taken through the plane marked 13-13of the second protection zone of the inflatable curtain airbag of FIG.11 in the deployed configuration.

DETAILED DESCRIPTION

Exemplary embodiments of the present invention will be best understoodby reference to the drawings, wherein like parts are designated by likenumerals throughout. It will be readily understood that the componentsof the present invention, as generally described and illustrated in theFigures herein, could be arranged and designed in a wide variety ofdifferent configurations. Thus, the following more detailed descriptionof the embodiments of the apparatus, system, and method of the presentinvention, as represented in FIGS. 1 through 12, is not intended tolimit the scope of the invention, as claimed, but is merelyrepresentative of exemplary embodiments of the invention.

The phrases “connected to,” “coupled to” and “in communication with”refer to any form of interaction between two or more entities, includingmechanical, electrical, magnetic, electromagnetic, fluid, and thermalinteraction. Two components may be coupled to each other even thoughthey are not in direct contact with each other. The term “abutting”refers to items that are in direct physical contact with each other,although the items may not necessarily be attached together. The phrase“fluid communication” refers to two features that are connected suchthat a fluid within one feature is able to pass into the other feature.“Exemplary” as used herein means serving as a typical or representativeexample or instance, and does not necessarily mean special or preferred.

Inflatable airbag systems are widely used to minimize occupant injury ina collision scenario. Airbag modules have been installed at variouslocations within a vehicle, including, but not limited to, the steeringwheel, the instrument panel, within the side doors or side seats,adjacent to the roof rail of the vehicle, in an overhead position, or atthe knee or leg position. In the following disclosure, “airbag” mayrefer to any airbag type.

Referring to FIG. 1, an airbag assembly 100 may be used to protect thepassengers of a vehicle during a side collision or roll-over collision.The vehicle may have a longitudinal direction 101 oriented along thelength of the vehicle, a lateral direction 102 oriented from one side ofthe vehicle to the opposing side, e.g., into and out of the page in theview of FIG. 1, and a transverse direction 103 oriented upward anddownward. The terms “inboard” and “outboard” may be used to refer to theposition of an object along the lateral direction 102. “Outboard”relates to placement of an object relatively closer than a second objectto a lateral plane of the vehicle, which is either of two planesperpendicular to the lateral direction 102, one of which barely touchesthe very leftward terminus of the vehicle, and the other of which barelytouches the very rightward terminus of the vehicle. “Inboard” relates toplacement of an object relatively closer than a second object to amedial plane of the vehicle, which is the plane perpendicular to thelateral direction 102 that bisects the vehicle into two equal halves.“Inboard” and “outboard” do not require alignment of the two objects inthe lateral direction 102; rather, these terms simply relate toproximity to the lateral or medial planes as set forth above.

The terms “rearward” and “forward” relate to the relative positions ofthe objects along the longitudinal direction 101. “Forward” relates toplacement of an object relatively closer than a second object to afrontal plane of the vehicle, which is a plane perpendicular to thelongitudinal direction 101 that barely touches the very frontwardterminus of the vehicle. Similarly, “rearward” relates to placement ofan object relatively closer than another object to a rear plane of thevehicle, which is a plane perpendicular to the longitudinal direction101 that barely touches the very rearward terminus of the vehicle. Anobject that is “forward” of a second object need not be aligned with thesecond object in the longitudinal direction 101; it simply means thatthe first object is closer to the frontal plane of the vehicle than thesecond object. The term “rearward” similarly does not require alignmentin the longitudinal direction 101.

The term “lateral” refers to a direction, object, or surface thatpertains to the lateral direction 102. The “lateral surfaces” of thevehicle are the interior surfaces of the vehicle that face generally(but not necessarily precisely) toward the medial plane of the vehicle.

The airbag assembly 100 may include an inflator 104, a tube 106, and aninflatable curtain airbag 110 that receives gas from the inflator 104via the tube 106. The airbag assembly 100 may also have a sensor and acontrol system (not shown) that detects a collision or impendingcollision and transmits an activation signal to the inflator 104. Theinflator 104 may be one of several types, such as pyrotechnic, storedgas, or a combination inflator and may be a single or multistageinflator. The inflator 104 may be stored at any suitable locationrelative to the inflatable curtain airbag 110. If the inflator 104 is apyrotechnic inflator, the inflator 104 may contain a propellant thatignites to rapidly produce inflation gas in response to receipt of theactivation signal.

The inflatable curtain airbag 110 may extend along the longitudinaldirection 101 within the vehicle. The inflatable curtain airbag 110 maybe coupled to or next to a roof rail 112 of the vehicle. The airbagassembly 100 may also include a forward tether 108 and a rear tether 109that are coupled proximate the front and rear ends, respectively, of theinflatable curtain airbag 110. Upon inflation of the inflatable curtainairbag 110, the forward tether 108 and the rear tether 109 may providetension that helps keep the inflatable curtain airbag 110 in place.

In the event of a collision, the inflatable curtain airbag 110 mayexpand downward along the side of the vehicle between the vehiclepassengers and one or more lateral surfaces of the vehicle such as theside windows and pillars (the structures between the lateral windowsand/or the windshield and rear window) of the vehicle. The pillars mayinclude an A-pillar 114, a B-pillar 116, a C-pillar 118, and, ifpresent, a D-pillar 119, all of which may join the roof rail at theirupper ends. In some embodiments, an inflatable curtain airbag may extendfrom an A-pillar to a C-pillar of the vehicle. In other embodiments suchas that illustrated in FIG. 1, the inflatable curtain airbag 110 mayextend from the A-pillar 114 to a D-pillar 119 of the vehicle.

In addition to the airbag assembly 100, other airbags may be installedin the vehicle. For example, a separate driver's side airbag (not shownin FIG. 1) may be used to protect an occupant (i.e., the driver) fromimpact with various forward surfaces of the vehicle, including thesteering wheel 121 and instrument panel 122. The airbag assembly 100 mayprovide supplemental protection by cushioning impact not only againstthe lateral surfaces mentioned previously, but also cushioning impactagainst the A-pillar and/or an outboard portion 123 of the instrumentpanel 122. The outboard portion 123 is the portion of the instrumentpanel 122 that lies generally outboard of the steering wheel 121.

The inflatable curtain airbag 110 may normally reside in a stowedconfiguration, in which the inflatable curtain airbag 110 is concealedbehind the interior trim of the vehicle, such as the lateral headlinertrim (the trim that covers the edges of the headliner, which istypically a sheet of fabric that covers the interior of the vehicleroof). Prior to installation in the vehicle, the inflatable curtainairbag 110 may be compacted into the stowed configuration, such as byrolling, folding, or a combination thereof, such that the inflatablecurtain airbag 110 assumes an elongated shape extending along a pathwaywith a length that is much greater than the height or width of itscross-sectional shape.

Once compacted into the stowed configuration, the inflatable curtainairbag 110 may be retained in the stowed configuration through the useof wrappers, fasteners, or the like to facilitate shipping andinstallation. The inflatable curtain airbag 110 may be secured to thevehicle proximate the roof rail 112. In the embodiment of FIG. 1,integrated wrappers and fastening systems may be provided in the form ofa plurality of mounting assemblies 120 distributed along the length ofthe inflatable curtain airbag 110. Each of the mounting assemblies 120may include a tab 124 secured to the inflatable curtain airbag 110, afastener 125 that secures the tab 124 to the roof rail 112, and awrapper 126 that encircles the inflatable curtain airbag 110 to keep theinflatable curtain airbag 110 in the stowed configuration untildeployment.

In alternative embodiments, different mounting assemblies may be used.Such mounting assemblies may include tabs that are integrally formedwith the inflatable curtain airbag, alternative fasteners, or the like.The wrappers 126 may not be present in all embodiments; otherembodiments may utilize different features or attachment methods to keepthe inflatable curtain airbag compacted. Such wrappers or other featuresmay be independent of the mounting assemblies used to secure theinflatable curtain airbag to the vehicle.

As shown, the inflatable curtain airbag 110 may have a first protectionzone 130 secured to the roof rail 112 and a second protection zone 132secured to the pillar 114. Thus, the mounting assemblies 120 may bearranged along the length of the inflatable curtain airbag 110 from arear location on or near the D-pillar to a forward location proximate aforward end of the A-pillar 114.

Upon activation, the inflator 104 may generate and/or release inflationgas into the tube 106. From the tube 106, the inflation gas may rapidlyenter the inflatable curtain airbag 110, thereby causing the inflatablecurtain airbag 110 to begin expanding. In response to the expansion, thewrappers 126 may break to release the inflatable curtain airbag 110.Thus, the inflatable curtain airbag 110 may exit the stowedconfiguration and assume an extended shape. This process is called“deployment.” When deployment is complete, the inflatable curtain airbag110 may be said to be in a deployed configuration, as will be shown anddescribed in FIG. 2.

Referring to FIG. 2, a perspective view illustrates the airbag assembly100, wherein the inflatable curtain airbag 110 is in the deployedconfiguration. The inflatable curtain airbag 110 may inflate uponactivation of the inflator 104 and/or other optional inflators such thatthe inflatable curtain airbag 110 transitions from the stowedconfiguration to the deployed configuration. During deployment, thewrapper 126 may tear such that inflatable curtain airbag 110 can exitthe stowed configuration. The inflatable curtain airbag 110 may alsoextend past a B-pillar 116 and a C-pillar 118 such that in a deployedconfiguration, the inflatable curtain airbag at least partially coversthe B-pillar 116 and the C-pillar 118, as depicted in FIG. 2. Theinflatable curtain airbag 110 may also cover a portion of the D-pillar119.

FIG. 2 illustrates the positioning of the first protection zone 130 andthe second protection zone 132. The first protection zone 130 maygenerally cover the lateral surfaces of the vehicle from the steeringwheel rearward, while the second protection zone 132 covers the lateralsurfaces forward of the steering wheel. The inflatable curtain airbag110 may have an upper portion 134 and a lower portion 136.

The inflatable curtain airbag 110 may be generally formed from twolayers of flexible material such as a fabric or thin polymer, and mayinclude an inboard section 138, and an outboard fabric layer in the formof an outboard section 139 (visible in FIG. 3). The inboard section 138and the outboard section 139 may constitute a first fabric layer and asecond fabric layer, respectively. According to one example, theinflatable curtain airbag 110 is generally made from a woven nylonfabric, but other fabrics or flexible materials may be used. The inboardsection 138 and the outboard section 139 may be separate pieces offabric, or may be sections of a single piece of fabric folded together.The inboard section 138 and the outboard section 139 may be securedtogether at a peripheral juncture, for example, via peripheral stitching144, as shown. In the alternative, the inboard section 138 and theoutboard section 139 may be secured together via mechanical fastening,adhesives, one-piece weaving, RF welding, ultrasonic welding, or anyother suitable method known in the art.

The inboard section 138 and the outboard section 139 of the inflatablecurtain airbag 110 may define a first chamber 140 within the firstprotection zone 130 and a second chamber 142 within the secondprotection zone 132. A “chamber” may be defined as an interior cavitywithin a body. The first chamber 140 may receive inflation gas from theinflator 104 via the fill tube 106. The second chamber 142 may receiveinflation gas from the first chamber 140. As shown, the first chamber140 may be divided into inflation cells 146 via interior stitching 148.

Referring to FIG. 3, a top view illustrates the airbag assembly 100 withthe inflatable curtain airbag 110 in the deployed configuration.Additionally, FIG. 3 illustrates an occupant zone 160 that wouldordinarily be occupied by a vehicle occupant's head, or morespecifically, the driver's head, along with a deployed position 162 ofan exemplary driver's side airbag.

Additionally, FIG. 3 shows a forward trajectory 170, an outboardtrajectory 172, and a forward outboard trajectory 174 of the occupant'shead relative to the vehicle. The forward trajectory 170 is where thehead may move from the occupant zone 160 during an ordinary (i.e., notsmall overlap or oblique) frontal collision. The outboard trajectory 172is where the head may move from the occupant zone 160 during a sideimpact, such as an impact against the side of the vehicle along whichthe inflatable curtain airbag 110 inflates. The forward outboardtrajectory 174 is where the head may move from the occupant zone 160during a small overlap or oblique collision.

As shown, the forward outboard trajectory 174 results from a rotation ofthe vehicle caused by the small overlap or oblique collision and maytend to move the occupant's head outboard of the steering wheel 121 toimpact the A-pillar 114 and/or the outboard portion 123 of theinstrument panel 122. Some vehicles may have doors that extend forwardof the steering wheel 121, and accordingly, may have door trim or otherdoor portions that may also be impacted in the event of a small overlapor oblique collision. The presence of the second protection zone 132 mayserve to protect the head from such an impact. Thus, the secondprotection zone 132 may enable the airbag assembly 100 to provideenhanced protection in the event of a rollover or small overlap oroblique collision.

Depending on the layout of the interior stitching 148, the secondprotection zone 132 may inflate generally simultaneously with the firstprotection zone 130, or may only inflate after inflation of the firstprotection zone 130 has substantially completed. If the interiorstitching 148, or more specifically, a chamber divider 150 of theinterior stitching 148, is positioned to restrict inflation gas flowfrom the first protection zone 130 into the second protection zone 132,inflation of the second protection zone 132 may be delayed to the extentdesired.

The second protection zone 132 may interact with the various interiorstructures of the vehicle, such as the A-pillar 114, the instrumentpanel 122, and the steering wheel 121. For example, the secondprotection zone 132 may butt up against any of these structures duringdeployment to provide some frictional engagement that helps the secondprotection zone 132 to remain in place during the potential impact ofthe occupant's head with the second protection zone 132.

The airbag assembly 100 is shown in use on the driver's side of thevehicle. A similarly configured (i.e., mirror image or near-mirrorimage) airbag assembly may be used on the passenger's side of thevehicle in addition or in the alternative to the airbag assembly 100.Such an airbag assembly may have a second protection zone similar to thesecond protection zone 132 to protect the front passenger from impactagainst the interior surfaces that correspond to the A-pillar 114, thesteering wheel 121, and the outboard portion 123 of the instrument panel122. For example, the passenger's side may have an A-pillar, glovecompartment, dashboard, and/or instrument panel that may be beneficiallycovered by such a second protection zone.

The configuration of the airbag assembly 100 is merely exemplary. Avariety of types and configurations of inflatable curtain airbags may beutilized within the scope of the present disclosure. For example, inalternative embodiments, varying sizes, shapes, and proportions ofinflatable curtain airbags may be used. An automaker may select fromsuch alternative embodiments based on the desired location within thevehicle, the anticipated collision type and severity, the likely habitsof vehicle occupants, and any other criteria recognized by those ofskill in the automotive safety arts.

In the embodiment of FIGS. 1-3, the second protection zone 132 maygenerally be stowed within the trim attached to the A-pillar 114. Thismay be suitable for some vehicles. However, in some embodiments, it maybe desirable to minimize the airbag structure stowed on and/or securedto the A-pillar 114. Some vehicles, and in particular, compact cars, mayhave very limited space within the trim attached to the A-pillar 114.Additionally, it may be desirable to minimize the risk that any A-pillartrim elements or other components will be projected into the vehicleinterior during deployment. Hence, in alternative embodiments, a secondprotection zone may be stored elsewhere.

Referring to FIG. 4, a side elevation view illustrates an airbagassembly 200 according to an alternative exemplary embodiment of theinvention, with an inflatable curtain airbag 210 in a stowedconfiguration within a vehicle. Like the airbag assembly 100, the airbagassembly 200 may include an inflator 104 connected to the inflatablecurtain airbag 210 via a tube 106, and a forward tether 108 and a reartether 109 that cooperate to provide tension to keep the inflatablecurtain airbag 210 in position upon deployment. The inflatable curtainairbag 210 may be secured to the roof rail 112 via a plurality ofmounting assemblies 120, each of which may include a tab 124, a fastener125, and a wrapper 126. As in the previous embodiment, the wrappers 126may break open during initial inflation of the inflatable curtain airbag210 to permit deployment of the inflatable curtain airbag 210.

The inflatable curtain airbag 210 may be designed to minimize the needfor storage of or attachment of airbag components to the A-pillar 114.Thus, the inflatable curtain airbag 210 may have a design in which theportions of the inflatable curtain airbag 210 that deploy forward of thesteering wheel 121 are positioned adjacent to the forward portion of theroof rail 112 rather than stored within the trim on the A-pillar 114.More specifically, the inflatable curtain airbag 210 may have a firstprotection zone 230 that deploys generally rearward of the steeringwheel 121, and a second protection zone 232 that deploys generallyforward of the steering wheel 121. In the stowed configuration, thesecond protection zone 232 may be folded rearward to overlie the firstprotection zone 230. The term “overlie” refers to two objects withoutward-facing surfaces that are positioned against each other.

Thus, the package defined by the inflatable curtain airbag 210 in thestowed configuration of FIG. 4 may be somewhat larger proximate theforward portion of the roof rail 112 than that of the inflatable curtainairbag 110 of the previous embodiment. None of the mounting assemblies120 need be secured to the A-pillar 114. This leaves the A-pillar 114free of airbag components apart from the forward tether 108. This mayminimize the bulk of material stored within the trim on the A-pillar114. Further, such a configuration may enhance the overall safety levelof the airbag assembly 200 by reducing the risk of airbag componentsbeing projected from the A-pillar or the A-pillar trim during deploymentof the airbag assembly 200.

In alternative embodiments of the invention, only one of the mountingassemblies (i.e., the forward-most mounting assembly) may be secured tothe A-pillar. Many of the benefits cited above may still be obtainedwith such a configuration, particularly if the A-pillar trim is largertoward its juncture with the roof rail, thereby leaving more space atthe top end of the A-pillar.

Referring to FIG. 5, a side elevation view illustrates the airbagassembly 200 of FIG. 4, with the inflatable curtain airbag 210 in thedeployed configuration. Deployment may initially occur substantially asset forth above in the description of the airbag assembly 100 of FIGS.1-3. Thus, as shown, the wrappers 126 may break open to release theinflatable curtain airbag 210, and the inflatable curtain airbag 210 mayextend downward to protect occupants of the vehicle from impact againstthe lateral surfaces of vehicle.

As shown, the inflatable curtain airbag 210 has a configurationgenerally similar to that of the inflatable curtain airbag 110, withsome differences. The inflatable curtain airbag 210 may have an upperportion 234 and a lower portion 236. The inflatable curtain airbag 210may be formed by an inboard section 238 and an outboard section 239 thatare secured together through any of the methods mentioned previously ata peripheral juncture, for example, with peripheral stitching 244. A“peripheral juncture” may be any feature by which inboard and outboardelements are joined to define an interior chamber. Thus, the peripheralstitching 244 is only one of many possible embodiments of a peripheraljuncture. Other embodiments include an ultrasonically welded juncture, aone-piece woven juncture, an adhesive or chemically bonded juncture, amechanically fastened juncture, an RF welded juncture, and the like.

The inboard section 238 and the outboard section 239 may constitute afirst fabric layer and a second fabric layer, respectively. Interiorstitching 248 may be applied interior to the peripheral stitching 244.The inboard section 238 and the outboard section 239 may cooperate todefine a first chamber 240 within the first protection zone 230 and asecond chamber 242 within the second protection zone 232. The boundariesof the first chamber 240 and the second chamber 242 may be defined bythe geometry of the peripheral stitching 244 and the interior stitching248.

The inflatable curtain airbag 210 may not have inflation cells like theinflation cells 146 of the previous embodiment, but may, instead, have aplurality of non-inflating regions 246 defined by the interior stitching248. The non-inflating regions 246 may be positioned proximate areaswhere impact from a vehicle occupant is unlikely, or where it isdesirable to attach a tether or another airbag component. Suchattachment may beneficially be done at the non-inflating regions 246because the attachment can be carried out through the inboard section238 and the outboard section 239 without impeding the inflation of theinflatable curtain airbag 210. The non-inflating regions 246 may alsoserve to reduce the volume of the inflatable curtain airbag 210 in thedeployed configuration, thereby reducing the amount of inflation gasrequired, and thence, the size of the inflator 104.

A chamber divider 250 of the interior stitching 248 may be positionedbetween the first protection zone 230 and the second protection zone232, and may thus separate the first chamber 240 from the second chamber242. The chamber divider 250 may restrict the flow of inflation gas fromthe first chamber 240 into the second chamber 242, and may thus causethe first protection zone 230 to inflate generally prior to inflation ofthe second protection zone 232.

The second protection zone 232 may be much different from the secondprotection zone 132 of the previous embodiment in that the secondprotection zone 232 may be much more compact, and may be relativelynarrow when deployed. This may help ensure that the inflatable curtainairbag 210, and particularly the enlarged, forward portion of theinflatable curtain airbag 210 where the second protection zone 232overlies the first protection zone 230, compacts into the space providedfor it in the trim for the roof rail 112.

During deployment, the inflation of the first protection zone 230 andthe second protection zone 232 may cause the second protection zone 232to generally pivot forward from its stowed position overlying the firstprotection zone 230. Thus, the second protection zone 232 may firstpivot inboard until it extends in the lateral direction 102, wherein itis generally perpendicular to the first protection zone 230. From thisposition, the second protection zone 232 may continue to pivot forward,but now may pivot outboard. If left unchecked, this motion may continueuntil the second protection zone 232 is generally parallel to the firstprotection zone 230.

If the second protection zone 232 is permitted to fully unfold, i.e.,pivot outboard until it is generally parallel to the first protectionzone 230, it may no longer be optimally positioned to prevent impact ofthe occupant in the event of a small overlap collision. More precisely,such positioning may allow the driver's head to move along the forwardoutboard trajectory 174 as shown in FIG. 3, and move between the secondprotection zone 232 and the driver's side airbag. Thus, it is desirableto provide some mechanism for keeping the second protection zone 232 atan angle of less than 180° relative to the first protection zone 230, asviewed from the top. This angle will be shown in greater detail in FIG.7.

A restraint member may be used to keep the second protection zone 232from pivoting outboard into a position parallel to the first protectionzone 230. A “restraint member” may be defined as any structure thatserves to restrict the position and/or orientation of an object. In theairbag assembly 200, the restraint member may limit outboard motion ofthe second protection zone 232 during deployment.

In the airbag assembly 200, the restraint member may take the form of atether 280 with a first end 282 secured to the first protection zone 230and a second end 284 secured to the second protection zone 232. Thefirst end 282 may be secured proximate a top edge of the firstprotection zone 230, and may be secured to the first protection zone 230itself, or to a part of the vehicle such as the roof rail 112. In FIG.5, the first end 282 is secured to one of the mounting assemblies 120,and may thus be secured to the roof rail 112 with the fastener 125 usedto secure the tab 124 of the mounting assembly 120 to the roof rail 112.The second end 284 may be secured directly to the top edge of the secondprotection zone 232.

In alternative exemplary embodiments, such a restraint member may have avariety of configurations including flexible members such as cords ortethers, or rigid members such as rails, brackets, or the like. A rail(not shown) may have a sliding element such as a ring connected to thecushion, and may be secured proximate the roof of the vehicle to limitoutboard and/or forward motion of the second protection zone 232. Abracket (not shown) or other hard stop may deploy downward from thevehicle roof to directly block forward and/or outboard motion of thesecond protection zone 232. Those of skill in the art will recognizethat many other alternative devices may be used to restrict forwardand/or outboard motion of the second protection zone 232.

Referring to FIG. 6, a side elevation view illustrates the forwardportion of the inflatable curtain airbag 210 of the airbag assembly 200of FIG. 4, prior to compaction of the inflatable curtain airbag 210 intothe stowed configuration. As shown, the chamber divider 250 may extendalong most of the height of the inflatable curtain airbag 210 betweenthe first chamber 240 and the second chamber 242. The forward tether 108may have first end 286 secured to the inflatable curtain airbag 210 anda second end 288 securable to the vehicle. The first end 286 may besecured to the chamber divider 250, and more specifically, may besecured to a non-inflating region 246 that extends from the remainder ofthe chamber divider 250. The first end 286 may be secured to the region246 via stitching 287. The second end 288 may have a hole 289 or otherfeature that facilitates attachment of the second end 288 to theA-pillar 114, for example, through the use of a fastener (not shown).

The chamber divider 250 may also form a natural fold line where, in thedeployed configuration, the inflatable curtain airbag 210 is able toremain partially folded. It may be difficult to fold the inflatablecurtain airbag 210 at other locations because the pressure of theinflation gas within the inflatable curtain airbag 210 and the manner inwhich the inflatable curtain airbag 210 bulges outward in the lateraldirection 102 may tend to keep most regions of the inflatable curtainairbag 210 from bending away from the longitudinal direction 101.However, as the chamber divider 250 may extend along most of the heightof the inflatable curtain airbag 210, the chamber divider 250 mayprovide a natural fold line.

The second chamber 242 of the second protection zone 232, as shown, is asingle chamber. However, it should be understood that the second chamber242 could be divided into multiple chambers without departing from thespirit of the invention. For example, the second chamber 242 could bedivided into two adjacent chambers, a forward most chamber and anintermediate chamber. The intermediate chamber could have the chamberdivider 250 at one side and the divider between the forward most chamberand the intermediate chamber at the other side. An airbag configurationwith an intermediate chamber and a forward most chamber may align betteralong the contour of the side door, A-pillar, and instrument panel. Oneembodiment of the invention could have the intermediate chamberpositioned to cushion the vehicle occupant from impacting the A-pillarand the forward most chamber positioned to cushion the vehicle occupantfrom impacting the instrument panel. Of course, a person of skill in theart, armed with the present disclosure, could determine a configurationusing multiple chambers that would protect a vehicle occupant for aparticular vehicle configuration.

The inflatable curtain airbag 210 may be folded at a stowed fold line290 to compact it into the stowed configuration. As shown in FIG. 6, thestowed fold line 290 is the same as the natural fold line (i.e., thedeployed fold line), and is thus defined by the chamber divider 250. Inalternative embodiments, the inflatable curtain airbag 210 may be foldedat a different location, i.e., either forward or rearward of the chamberdivider 250. The location of the stowed fold line may have little impacton the deployed configuration of the inflatable curtain airbag 210because the chamber divider 250 may determine where the fold is locatedin the deployed configuration.

The attachment location of the first end 286 of the forward tether 108may be selected to provide the desired level of tension on the secondprotection zone 232. More specifically, securing the first end 286forward of the chamber divider 250 may cause the forward tether 108 toexert tension in the longitudinal direction 101 on not only the firstprotection zone 230, but on the second protection zone 232 as well. Suchtension may help unfold the second protection zone 232 by helping pivotthe second protection zone 232 forward during deployment, but may alsoact to draw the second protection zone 232 toward a position in whichthe second protection zone 232 is parallel to the first protection zone230. As set forth above, this may not be desirable.

Securing the first end 286 rearward of the chamber divider 250 may causethe forward tether 108 to exert tension in the longitudinal direction101 on only the first protection zone 230. Securing the first end 286directly on the chamber divider 250, or forward of, but close to, thechamber divider 250, may cause the forward tether 108 to exert somelevel of tension on the second protection zone 232, but with a shortmoment arm so that the resulting moment tending to pivot the secondprotection zone 232 forward is relatively small.

Hence, the attachment point of the first end 286 may be carefullyselected to obtain the desired balance between expeditious deployment ofthe second protection zone 232 and maintenance of the second protectionzone 232 at the proper orientation to provide protection in the event ofa small overlap, oblique, or rollover collision. In the embodiment ofFIG. 6, the first end 286 may be secured to the non-inflating region 246of the chamber divider 250, which extends generally rearward of theremainder of the chamber divider 250. Thus, as configured in FIG. 6, theforward tether 108 may exert little, if any, longitudinal tension on thesecond protection zone 232.

The second end 284 of the tether 280 may be secured to a top edge 294 ofthe second protection zone 232, for example, via stitching 285. Thesecond end 284 may be secured above the peripheral stitching 244 at thetop of the second protection zone 232 so that the stitching 285 securingthe second end 284 to the second protection zone 232 can extend throughthe inboard section 238 and the outboard section 239 without impedinginflation of the second protection zone 232.

The second end 284 may be secured to the top edge 294 at a locationapproximately equidistant from the deployed fold line, or the chamberdivider 250, and a forward edge 292 of the second protection zone 232.Thus, the second end 284 may be secured at a location generally near thecenter of the second protection zone 232 in the longitudinal direction101. This location may provide a balance between conserving tethermaterial, which would favor attachment closer to the chamber divider250, and providing a long moment arm to keep the second protection zone232 in place in the event of relatively high-velocity motion of theoccupant.

It may be desirable to moderate this moment arm to avoid keeping thesecond protection zone 232 in place too rigidly. More specifically, itmay be advantageous to provide some ability for the second protectionzone 232 to pivot outboard, toward a position parallel to the firstprotection zone 230, to soften the impact of the occupant against thesecond protection zone 232. The location of the second end 284 may becarefully selected to strike the optimal balance between rigidity andflexibility in the position of the second protection zone 232.

From the configuration of FIG. 6, the inflatable curtain airbag 210 mayneed to be at least partially compacted prior to attachment of the firstend 282 of the tether 280 to the mounting assembly 120 that correspondsto it (i.e., the mounting assembly 120 on the left in FIG. 6) becausethe tether 280 may not be long enough to be simultaneously attached tothe mounting assembly 120 and the desired location on the top edge 294with the inflatable curtain airbag 210 laid flat as shown.

According to one example, with the second end 284 secured to the topedge 294 as shown, the inflatable curtain airbag 210 may be foldedinboard at the stowed fold line 290. Thus, the forward edge 292 may bebrought inboard, or out of the page with reference to the view of FIG.6, and then brought rearward (or to the left in the view of FIG. 6)until the forward edge 292 overlies the corresponding region of thefirst protection zone 230. The fold line 290 may then be the forwardedge of the inflatable curtain airbag 210. The first end 282 of thetether 280 may then be secured to the tab 124 of the mounting assembly120. In the alternative, this may be done when the airbag assembly 200is installed in the vehicle.

After the inflatable curtain airbag 210 has been folded in thelongitudinal direction 101, the inflatable curtain airbag 210 may berolled, folded, or otherwise compacted in the transverse direction 103.This may provide the elongated shape of the inflatable curtain airbag210 in the stowed configuration. With the inflatable curtain airbag 210in the stowed configuration, the mounting assemblies 120 may easily besecured to the roof rail 112 to install the inflatable curtain airbag210 in the vehicle. As mentioned previously, none of the mountingassemblies 120 need be secured to the A-pillar 114.

Referring to FIG. 7, a top view illustrates the airbag assembly 200 ofFIG. 4, wherein the inflatable curtain airbag 210 is in the deployedconfiguration. As shown, the second protection zone 232 has unfoldedfrom the first protection zone 230 to an extent limited by the tether280. The second protection zone 232 may be positioned to block the gapbetween the first protection zone 230 and the position 162 of thedriver's side airbag. The second protection zone 232 may thus bepositioned generally between the occupant zone 160 of the occupant'shead and the A-pillar 114 and the outboard portion 123 of the instrumentpanel 122, thereby providing protection from impact against thesesurfaces.

As shown, the inflatable curtain airbag 210 may remain folded at thechamber divider 250, which defines the natural fold line of theinflatable curtain airbag 210. As mentioned previously, the stowed foldline of the inflatable curtain airbag 210 may also be at the chamberdivider 250, but in alternative embodiments, this need not be the case.A natural fold line at a different location from the chamber divider 250may or may not affect the configuration of the deployed inflatablecurtain airbag.

As shown in FIG. 7, the second protection zone 232 may unfold at anangle 296 relative to the first protection zone 230. The angle 296 maybe determined by the length and attachment locations of the tether 280.The angle 296 may advantageously be less than 180°. The angle 296 mayfall within the range of 110° to 160°. More precisely, the angle 296 mayfall within the range of 120° to 150°. Yet more precisely, the angle 296may fall within the range of 130° to 140°. Still more precisely, theangle 296 may be about 135°.

Some impacts may lead to what is known as Z-axis rotation of the head ofthe vehicle occupant in the occupant zone 160, as indicated by the arrow298. Z-axis rotation, if excessive, may result in injury to the headand/or neck (not shown) of the vehicle occupant. In certain embodiments,inflatable curtain airbags according to the present invention may bedesigned to reduce and/or minimize Z-axis rotation.

Referring to FIG. 8, a side elevation view illustrates the forwardportion of an inflatable curtain airbag 310 of an airbag assemblyaccording to one alternative embodiment of the invention, prior tocompaction of the inflatable curtain airbag 310 into the stowedconfiguration. The inflatable curtain airbag 310 may have a plurality ofmounting assemblies 320 arranged along its length to facilitateattachment of the inflatable curtain airbag 310 to the vehicle. Each ofthe mounting assemblies 320 may have a tab 324, and optionally, othercomponents like those described in the description of the mountingassemblies 120. If desired, all of the mounting assemblies 320 may besecured rearward of the A-pillar 114. Alternatively, one (i.e., theforward-most) of the mounting assemblies 320 may be secured to theA-pillar 114 adjacent to the roof rail 112.

Like the inflatable curtain airbag 210, the inflatable curtain airbag310 may have a first protection zone 330 and a second protection zone332 that unfolds forward of the first protection zone 330. Theinflatable curtain airbag 310 may have an upper portion 334, a lowerportion 336, an inboard section 338, and an outboard section 339 (facingaway from the viewpoint of FIG. 8). The inboard section 338 and theoutboard section 339 may constitute a first fabric layer and a secondfabric layer, respectively. The inboard section 338 and the outboardsection 339 may be secured together to define a first chamber 340 withinthe first protection zone 330 and a second chamber 342 within the secondprotection zone 332. The inboard section 338 and the outboard section339 may be secured together at a peripheral juncture, for example,through the use of peripheral stitching 344. The peripheral stitching344 may be particularly applicable to a cut-and-sewn airbag like theexemplary inflatable curtain airbag 310 of FIG. 8. However, as will beset forth in greater detail subsequently, other embodiments (not shown)may use different technologies to secure inboard and outboard layerstogether. For example, one-piece weaving technologies may be used, andmay unify the inboard and outboard layers at the periphery of the airbagin such a manner that there is no stitching or seam.

Returning to the example of FIG. 8, interior stitching 348 may also beapplied interior to the peripheral stitching 344, and may define one ormore non-inflating regions 346. The second protection zone 332 may havea forward edge 392, a top edge 394, a bottom edge 396, and a rearwardedge (not shown).

The first protection zone 330 and the second protection zone 332 may beseparated from each other by a chamber divider 350, which may be definedby a non-inflating region 346 extending generally along the transversedirection 103. The non-inflating region 346 may extend along asubstantial portion of the height of the inflatable curtain airbag 310;accordingly, the non-inflating region 346 may define a deployed foldline about which the inflatable curtain airbag 310 may remain partiallyfolded after deployment. A stowed fold line 390 may be positioned at thechamber divider 350 so that the stowed fold line 390 is the same as thedeployed fold line defined by the chamber divider 350.

The inflatable curtain airbag 310 may be secured to the vehicle via aforward tether 308, which may have a first end 386 secure to theinflatable curtain airbag 310 proximate the chamber divider 350, forexample, via stitching 387, and a second end 388 that can be secured tothe A-pillar 114 of the vehicle. A restraint member in the form of atether 380 may be used to control the angle to which the secondprotection zone 332 unfolds relative to the first protection zone 330 ina manner similar to that of the tether 280 of the previous embodiment.The tether 380 may thus have a first end 382 that can be secured to oneof the mounting assemblies 320, such as the mounting assembly 320 thatis the second forward-most mounting assembly (the leftward mountingassembly in FIG. 8) at an appropriate time prior to, during, or aftercompaction of the inflatable curtain airbag 310. The tether 380 may alsohave a second end 384.

The inflatable curtain airbag 310 may be distinct from the inflatablecurtain airbag 210 in several respects. In the inflatable curtain airbag310, the second chamber 342 may fill from proximate its upper end. Thus,inflation gas may flow into the second chamber 342 between the upperedge of the non-inflating region 346 of the chamber divider 350 and theperipheral stitching 344 proximate the top edge 394. The passagewaypermitting gas into the second chamber 342 may be fairly broad, therebyallowing the second protection zone 332 to inflate rapidly. The secondprotection zone 332 may inflate simultaneously with inflation of thefirst protection zone 330, or with only a short delay therebetween.

Furthermore, the non-inflating region 346 that defines the chamberdivider 350 may be significantly broader along the longitudinaldirection 101 than the chamber divider 250 of the previous embodiment.This may help the inflatable curtain airbag 310 to remain folded at thechamber divider 350 at the desired angle (such as the angle 296 shown inconnection with the previous embodiment) during deployment because thefirst protection zone 330 and the second protection zone 332 may eachhave ample room to expand before the portion of the second protectionzone 332 adjacent to the chamber divider 350 engages the correspondingportion of the first protection zone 330. Such engagement may urge thesecond protection zone 332 to an orientation parallel to the firstprotection zone 330. The breadth of the chamber divider 350 may act inconcert with the tether 380 to help ensure that the second protectionzone 332 is able to remain at the optimal relative to the firstprotection zone 330.

Yet further, the geometry of the peripheral stitching 344 proximate thebottom end of the chamber divider 350 may also facilitate deployment ofthe inflatable curtain airbag 310 with the desired angle between thesecond protection zone 332 and the first protection zone 330. Thecurvature of the peripheral stitching 344 proximate the bottom end ofthe chamber divider 350 may serve to widen the chamber divider 350proximate the bottom end of the inflatable curtain airbag 310, and mayhelp to alleviate the longitudinal tension present in the bottom portionof the chamber divider 350 during the deployment process. This mayfurther allow the second protection zone 332 to remain at the properangle relative to the first protection zone 330.

The inflatable curtain airbag 310 may have a non-inflating peripheralregion, or a peripheral region 352, positioned outside the peripheralstitching 344. The peripheral region 352 may lie on the opposite side ofthe peripheral stitching 344 from the first chamber 340 and the secondchamber 342, and thus need not contain inflation gas. The inboardsection 338 and the outboard section 339 may be secured together withinthe peripheral region 352, or may be left generally unattached in theperipheral region 352.

The peripheral region 352 may have a top portion 354, a bottom portion356, a forward portion 358, and a rearward portion (not shown). Theperipheral stitching 344 may also have a top portion 364, a bottomportion 366, a forward portion 368, and a rearward portion (not shown).The top portion 354 may lie generally above the top portion 364, thebottom portion 356 may lie generally beneath the bottom portion 366, andthe forward portion 358 may lie generally forward of the forward portion368. Similarly, the rearward portion of the peripheral region 352 maylie generally rearward of the rearward portion of the peripheralstitching 344.

The tether 380 may be cut from the fabric of the top portion 354 of theperipheral region 352. Thus, as shown, the tether 380 may be formed as asingle piece with the top portion 354. The main body of the tether 380may be separated from the remainder of the top portion 354 of theperipheral region 352 by a slit 372. The slit 372 may terminate short ofthe second end 384 of the tether 380 so that the top portion 354 of theperipheral region 352 remains joined to and unitary with the tether 380at the second end 384.

The inflatable curtain airbag 310 may be formed by cutting or otherwisesevering the material of the inboard section 338 and the outboardsection 339 to define the edges of the inflatable curtain airbag 310,i.e., the forward edge 392, the top edge 394, the bottom edge 396, andthe rearward edge (not shown). This process may define the profile ofthe inflatable curtain airbag 310. Then, the same or a different cuttingor other severing process may be used to form the slit 372, therebydefining the tether 380 as distinct from the remainder of the topportion 354.

According to certain embodiments, inflatable curtain airbags may bedesigned to minimize the likelihood of certain collision situations. Forexample, an inflatable curtain airbag may be designed to cover a portionof the vehicle door to help protect against ejection of the occupantfrom the vehicle. Additionally or alternatively, an inflatable curtainairbag may have chambers shaped such that, upon deployment, the surfacesthat receive impact are properly angled to reduce Z-axis rotation of thehead (as mentioned in the description of FIG. 7 and indicated by thearrow 298). Additionally or alternatively, an inflatable curtain airbagmay have chambers shaped to help counteract the tendency of theoccupant's head to slide downward along the surface of the inflatablecurtain airbag, which may lead to injury due to impact of the headagainst lower vehicle surfaces and/or excessive flexion or rotation ofthe neck. Some examples of such alternative embodiments will be shownand described in connection with FIGS. 9-12, as follows.

Referring to FIG. 9, a side elevation view illustrates the forwardportion of an inflatable curtain airbag 410 of an airbag assembly 400according to another alternative embodiment of the invention. As withprevious embodiments, the inflatable curtain airbag 410 may be securedproximate the roof rail of a vehicle (not shown) to protect one or morevehicle occupants from impact against a lateral surface of the vehicle.The inflatable curtain airbag 410 may be secured to the vehicle throughthe use of a plurality of mounting assemblies 420, which may beconfigured in a manner similar to those described previously, or mayhave a different configuration.

The inflatable curtain airbag 410 may have a first protection zone 430and a second protection zone 432 that inflate to provide the desiredimpact protection. The inflatable curtain airbag 410 may have an upperportion 434 and a lower portion 436. The inflatable curtain airbag 410may be formed from first and second fabric layers, which may be aninboard section 438 and an outboard section 439. The inboard section 438and the outboard section 439 may define a first chamber 440 within thefirst protection zone 430 and a second chamber 442 within the secondprotection zone 432.

The first chamber 440 and the second chamber 442 may be defined by aperipheral juncture that secures the inboard section 438 to the outboardsection 439. The peripheral juncture may be formed with a wide varietyof attachment methods and configurations including stitching, one-pieceweaving, RF welding, ultrasonic welding, mechanical fastening, adhesivebonding, chemical bonding, or the like. In FIG. 9, the peripheraljuncture may take the form of peripheral stitching 444 that generallyencircles the periphery of the inflatable curtain airbag 410.

The inflatable curtain airbag 410 may also have one or morenon-inflating regions 446 positioned within the space defined by theperipheral stitching 444. The non-inflating regions 446 may be definedby interior stitching 448 or alternatively, by a different form ofattachment (such as one-piece weaving, RF welding, ultrasonic welding,mechanical fastening, adhesive bonding, chemical bonding, and the like)by which the inboard section 438 and the outboard section 439 aresecured together within the space defined by the peripheral stitching444. One such non-inflating region 446 (i.e., the forward-mostnon-inflating region 446 shown in FIG. 9) may form an impediment betweenthe first chamber 440 and the second chamber 442. The impediment formedby the forward-most non-inflating region 446 may prevent gas flowbetween the lower portions of the first chamber 440 and the secondchamber 442, but may terminate below the top portions of the firstchamber 440 and the second chamber 442 so that inflation gas may enterthe top portion of the second chamber 442 from the top portion of thefirst chamber 440. The peripheral stitching 444 may have a top portion464, a bottom portion 466, a forward portion 468, and a rearward portion(not shown).

The airbag assembly 400 may also have a tether 408 that acts as a fronttether, which may cooperate with a rear tether (not shown) to maintaintension on the inflatable curtain airbag 410 to keep the inflatablecurtain airbag 410 in place after deployment. The tether 408 may have afirst end 486 secured to the inflatable curtain airbag 410, as shown inFIG. 9, and a second end 488 attachable to the vehicle, for example, atthe A-pillar 114.

The airbag assembly 400 may also have a tether 480 positioned proximatethe top portion 464 of the peripheral stitching 444 as shown. Like thetether 380 of the inflatable curtain airbag 310 of FIG. 8, the tether480 may help control the angle at which the second protection zone 432is positioned relative to the first protection zone 430 when the airbagassembly 400 is in the deployed configuration. More specifically, tether480 may cause the second protection zone 432 to be angled at less than180° relative to the first protection zone 430 when the airbag assembly400 is in the deployed configuration.

Thus, the tether 480 may have a first end 482, which may be secured toor unitarily formed with the inflatable curtain airbag 410 proximate theforward portion of the top portion 464. The tether 480 may also have asecond end (not shown), which may be attachable to the vehicle, forexample, at the roof rail 112. The second end may be attached at aposition on the roof rail 112 rearward of the first end 482.

The non-inflating region 446 that divides the second protection zone 432from the second chamber 442 may have a generally vertical portion 450and a generally horizontal portion 452. The generally vertical portion450 may extend upward, into the interior of the inflatable curtainairbag 410, from the bottom portion 466 of the peripheral stitching 444.The generally horizontal portion 452 may extend forward, toward theforward portion 468 of the peripheral stitching 444, from the top end ofthe generally vertical portion 450.

Thus, the non-inflating region 446 may, in addition to dividing thefirst chamber 440 from the second chamber 442 at the generally verticalportion 450, divide the second chamber 442 into an upper segment 470 anda lower segment 472 at the generally horizontal portion 452. The forwardend of the generally horizontal portion 452 may also be enlarged so asto define a forward segment 474 that extends between and provides fluidcommunication between the upper segment 470 and the lower segment 472.

During deployment, inflation gas may flow from the inflator 104 (notshown in FIG. 9) into the first chamber 440 through the tube 106, andfrom the first chamber 440 into the second chamber 442 through the spacebetween the top end of the generally vertical portion 450 of thenon-inflating region 446 and the top portion 464 of the peripheralstitching 444. From this space, the inflation gas may enter the secondchamber 442 through the upper segment 470. From the upper segment 470,the inflation gas may flow into the forward segment 474, and from theforward segment 474 downward into the lower segment 472. The rearwardend of the forward segment 474 may form a dead end.

The upper segment 470, the forward segment 474, and the lower segment472 may cooperate to define a non-branching passageway that conveysinflation gas through the second chamber 442. A “non-branchingpassageway” may be defined as a passage that conveys a fluid with nosignificant alternative flow pathways. Thus, the non-branchingpassageway defined by the upper segment 470, the forward segment 474,and the lower segment 472 may have no dividers, alcoves, sub-chambers,or other structures that would divert impact inflation gas flow throughthe main, generally U-shaped shape provided by the upper segment 470,the forward segment 474, and the lower segment 472.

The generally vertical portion 450 of the non-inflating region 446 mayhave a width 478 that is larger than strictly needed to serve as animpediment between the first chamber 440 and the second chamber 442. Thewidth 478 may be sufficient to leave a significant gap between the firstchamber 440 and the second chamber 442 such that, in the deployedconfiguration, the inflatable curtain airbag 410 is able to foldin-plane (i.e., within the plane in which the inflatable curtain airbag410 generally exists in the deployed configuration).

The width 478 may be within the range of 7 mm to 120 mm. The width 478may further be from 20 mm to 80 mm. The width 478 may be about 40 mm.

The in-plane folding may compress the width 478 to move the lower end ofthe first chamber 440 toward the lower end of the second chamber 442.This may occur due to the fact that the roof rail 112 and the A-pillar114 join at an angle of less than 180°, while the top portion 464 of theperipheral stitching 444 may be substantially straight. Thus, theinterior of the vehicle may exert reaction forces against the inflatablecurtain airbag 410 that urge the second protection zone 432 to tiltdownward relative to the first protection zone 430.

The width 478 of the non-inflating region 446 may facilitate thisdownward tilt, which may allow the inflatable curtain airbag 410 toprovide superior protection as will be shown and described in connectionwith FIG. 11. If desired, the in-plane folding of the inflatable curtainairbag 410 may be further encouraged by taking extra measures tocompress the width 478 after the inboard section 438 and the outboardsection 439 have been secured together.

For example, the generally vertical portion 450 may have a forwardportion 490 and a rearward portion 492. The forward portion 490 may beattached to the rearward portion 492 to compress the non-inflatingregion 446 by bringing the forward portion 490 and the rearward portion492 closer together. This may define a forward fold 494, a rearward fold496, and a compaction feature in the form of a central fold 498. Thiswill be further shown and described in connection with FIG. 10A.

Referring to FIG. 10A, an oblique section view illustrates the generallyvertical portion 450 of the non-inflating region 446 of the inflatablecurtain airbag 410 of FIG. 9 after attachment of the forward portion 490of the non-inflating region 446 to the rearward portion 492 of thenon-inflating region 446. The forward portion 490 may be attached to therearward portion 492 by an attachment feature, which may take the formof stitching 499.

The stitching 499 may be applied, for example, by first folding thegenerally vertical portion 450 to form the forward fold 494, therearward fold 496, and the central fold 498 in the non-inflating region446. The forward portion 490 may then overlie the rearward portion 492to form the V-shape illustrated in FIG. 10A. Then, the stitching 499 maybe applied through the forward portion 490 and the rearward portion 492to secure the forward portion 490 to the rearward portion 492.

FIG. 10A illustrates the forward fold 494, the rearward fold 496, andthe central fold 498 with what may be exaggerated roundness—they may becreased, or may be more rounded as shown. Additionally, Figureillustrates the existence of a significant gap between the forwardportion 490 and the rearward portion 492 after the stitching 499 isapplied; if desired, the stitching 499 may be drawn tight to close thegap and cause the forward portion 490 to directly abut the rearwardportion 492.

In other embodiments, the non-inflating region 446 may be cut to dividethe forward portion 490 from the rearward portion 492. The cut may be inplace of the central fold 498 shown in FIG. 10A. In such embodiments,the forward portion 490 and the rearward portion 492 may each be folded90° as in FIG. 10A; thus, the forward fold 494 and the rearward fold 496may be present substantially as shown in FIG. 10A, with the central fold498 replaced with a cut.

Referring to FIG. 10B, an oblique section view illustrates the generallyvertical portion 650 of a non-inflating region of an inflatable curtainairbag (not shown) according to another alternative embodiment of theinvention. The generally vertical portion 650 may have a forward portion690 and a rearward portion 692. The forward portion 690 may be separatedfrom the rearward portion 692 by a compaction feature in the form of acut 698 formed in the generally vertical portion 650 between the forwardportion 690 and the rearward portion 692. No folding operation may beneeded to compress the generally vertical portion 650. Rather, theforward portion 690 and the rearward portion 692 may remain in-planewith the remainder of the inflatable curtain airbag, and may be drawntogether in-plane such that they overlap with and overlie each other.Then, the forward portion 690 and the rearward portion 692 may beattached together by any method known in the art, including but notlimited to sewing, one-piece weaving, RF welding, ultrasonic welding,chemical bonding, adhesive bonding, and mechanical fastening. As shownin the exemplary embodiment of FIG. 10B, the forward portion 690 may besecured to the rearward portion 692 via stitching 698. This may serve tocompress the width 478 of the generally vertical portion 650 of thecorresponding non-inflating region in a manner similar that of theembodiment shown in FIG. 10A.

FIGS. 10A and 10B both provide compression of the width 478. Returningto the exemplary example of FIG. 10A, the compression of the width 478may cause the second protection zone 432 to tilt downward relative tothe first protection zone 430 in the deployed configuration, regardlessof the shape of the interior of the vehicle. This may offer significantbenefits, as will be shown and described in connection with FIG. 11, asfollows.

Referring to FIG. 11, a side elevation view illustrates the forwardportion of an inflatable curtain airbag 510 of an airbag assembly 500according to another alternative embodiment of the invention, in thedeployed configuration. The inflatable curtain airbag 510 may be similarto the inflatable curtain airbag 410 of FIG. 9, with mounting assemblies520, a first protection zone 530 with a first chamber 540, and a secondprotection zone 532 with a second chamber 542. The inflatable curtainairbag 510 may also have an upper portion 534 and a lower portion 536,and may be formed from an inboard section 538 and an outboard section539.

The inboard section 538 and the outboard section 539 may be securedtogether at a peripheral juncture, which may take the form of peripheralstitching 544. The peripheral stitching 544 may have a top portion 564,a bottom portion 566, a forward portion 568, and a rearward portion (notshown). The airbag assembly 500 may optionally have a tether like thetether 480 and/or a tether 408 like those of FIG. 9; such tethers arenot shown in FIG. 11 for clarity.

The inboard section 538 and the outboard section 539 may further besecured together by interior stitching 548 at a plurality ofnon-inflating regions 546, the forward-most of which may separate thefirst chamber 540 from the second chamber 542. This non-inflating region546 may have a generally vertical portion 550 and a generally horizontalportion 552, which may be similar to those of FIG. 9. However, as shown,the non-inflating region 546 of the inflatable curtain airbag 510 ofFIG. 11 may also have a terminal portion 554 that extends downward fromthe forward end of the generally horizontal portion 552.

The generally horizontal portion 552 may divide the second chamber 542into an upper segment 570 and a lower segment 572. The terminal portion554 may divide the second chamber 542 into a forward segment 574 and aterminal segment 576. The forward segment may extend generallyvertically to convey inflation gas between the forward ends of the uppersegment 570 and the lower segment 572. The terminal segment 576 mayextend generally upward from the rearward end of the lower segment 572and may terminate, at its upper end, in a dead end.

During deployment, inflation gas may flow from the inflator 104 (notshown in FIG. 9) into the first chamber 540 through the tube 106, andfrom the first chamber 540 into the second chamber 542 through the spacebetween the top end of the generally vertical portion 550 of thenon-inflating region 546 and the top portion 564 of the peripheralstitching 544. From this space, the inflation gas may enter the secondchamber 542 through the upper segment 570. From the upper segment 570,the inflation gas may flow into the forward segment 574, and from theforward segment 574 downward into the lower segment 572. The inflationgas may then flow rearward through the lower segment 572, and thenceinto the terminal segment 576. As mentioned, the top end of the terminalsegment 576 may form a dead end. The upper segment 570, the forwardsegment 574, the lower segment 572, and the terminal segment 576 maycooperate to define a non-branching passageway that conveys inflationgas through the second chamber 542.

As shown, the vehicle may have a roof rail 112 and an A-pillar 114 likethose shown in previous embodiments. A window 580 may be present, andmay extend under the forward portion of the roof rail 112 and therearward portion of the A-pillar 114. A door 582 may be positionedunderneath the window 580. The vehicle may also have a steering wheel584.

The in-plane bending of the inflatable curtain airbag 510 mayadvantageously cause the second protection zone 532 to extendsignificantly below the bottom of the window 580. The second protectionzone 532 may have an overlap 586 with the door 582 that, at its maximum,may be from 5 cm to 50 cm. The overlap 586 may further be from 10 cm to30 cm. The overlap 586 may be about 20 cm.

Thus, a significant portion of the second protection zone 532 may bepositioned directly inboard of the door 582. This overlap 586 may makeit more difficult for the impact of the occupant against the inflatablecurtain airbag 510 to push the inflatable curtain airbag 510 out of thevehicle through the window 580. This may, in turn help reduce thelikelihood of ejection of the occupant from the vehicle. Further, theoverlap 586 may help to more effectively cushion the vehicle occupantagainst impact with the door 582.

Referring to FIG. 12, an oblique section view through the plane marked12-12 in FIG. 11 illustrates the inflatable curtain airbag 510 of theairbag assembly 500 in the deployed configuration. As shown, asignificant portion of the second protection zone 532 may also bepositioned forward of the steering wheel 584. The forward portion of thesecond protection zone 532 may be angled inboard due to the operation ofa top tether like the tether 480 of FIG. 9 (not shown), and may bepositioned close to the deployed location of a frontal impact airbag(not shown) mounted in the steering wheel 584. Thus, the secondprotection zone 532 may help to reduce the possibility of the occupant'shead passing between the inflatable curtain airbag 510 and the frontalimpact airbag, which may tend to occur in small overlap collisionsituations. FIG. 12 illustrates the occupant zone 160 that may beoccupied by the occupant's head, and an arrow 588 indicating onepossible trajectory of the occupant's head toward the inflatable curtainairbag 510.

In addition to ejection mitigation and small overlap collisionprotection, the airbag assembly 500 may help reduce Z-axis rotation ofthe occupant's head, as shown and described in connection with FIG. 7.Z-axis rotation is further indicated by the arrow 589 in FIG. 12. Moreprecisely, the generally vertical portion 550 of the non-inflatingregion 546 may have a width 578, which may optionally be the same as orsimilar to the width 478 of the generally vertical portion 450 of thenon-inflating region 446 of FIG. 9. The width 578 may be large enough tofacilitate the in-plane bending of the inflatable curtain airbag 510,but not so large as to permit the generally vertical portion 550 todirectly receive the vehicle occupant's head, which may lead tostrikethrough and/or undesired Z-axis rotation of the head.

The geometry of the second chamber 542 may further enhance impactprotection by reducing the tendency of the occupant's head to slidedownward after striking the inflatable curtain airbag 510. The manner inwhich these benefits are achieved will be shown and described inconnection with FIG. 13, as follows.

Referring to FIG. 13, an oblique section view taken through the planmarked 13-13 in FIG. 11 illustrates the second protection zone 532 ofthe inflatable curtain airbag of FIG. 11 in the deployed configuration.FIG. 13 further illustrates how the inflatable curtain airbag 510 mayinflate inboard of the roof rail 112, the window 580, and the door 582.Overlap of the second protection zone 532 with the door 582 is alsoshown.

As mentioned previously, the generally horizontal portion 552 of thenon-inflating region 546 may separate the second chamber 542 into theupper segment 570 and the lower segment 572. This separation may causethe second chamber 542 to fold along the generally horizontal portion552 in a manner that angles the upper segment 570 and the lower segment572 toward each other, creating a slight V-shape as shown. Hence, theinboard section 538 of the lower segment 572 may present an exteriorsurface that is angled at least slightly upward. This may occur in spiteof the fact that the door 582 and/or the window 580 may curve inboardfrom bottom to top, which curvature may otherwise tend to angle theinboard surfaces of the inflatable curtain airbag 510 downward. With thesecond chamber 542 divided into the upper segment 570 and the lowersegment 572, the geometry of the door 582 and/or the window 580 mayactually help angle the exterior surface of the inboard section 538upward since the door 582 may protrude inboard, causing the segment 572to assume the angulation shown.

The head of the vehicle occupant, indicated by an occupant zone 160,may, during a collision, move outboard and downward as indicated by thearrow 590. The upward-facing exterior surface of the inboard section538, on the segment 572, may receive the impact and cause the head torebound upward again. This may help to prevent the injuries that couldotherwise occur if the head were to slide downward along the inboardsection 538 below the bottom of the second protection zone 532.

Thus, the airbag assembly 500 may help to reduce a wide variety ofpossible injury types. Further, the airbag assembly 500 may be effectivein a wide variety of collision types. The airbag assembly 500 may be forthe driver's side of the vehicle; a very similar structure may be usedfor the passenger's side (not shown). Alternatively, modifications maybe made to the passenger's side airbag assembly to help it moreeffectively cooperate with the interior vehicle structures and/orfrontal impact airbags of the passenger's side.

Any methods disclosed herein comprise one or more steps or actions forperforming the described method. The method steps and/or actions may beinterchanged with one another. In other words, unless a specific orderof steps or actions is required for proper operation of the embodiment,the order and/or use of specific steps and/or actions may be modified.

Reference throughout this specification to “an embodiment” or “theembodiment” means that a particular feature, structure or characteristicdescribed in connection with that embodiment is included in at least oneembodiment. Thus, the quoted phrases, or variations thereof, as recitedthroughout this specification are not necessarily all referring to thesame embodiment.

Similarly, it should be appreciated that in the above description ofembodiments, various features are sometimes grouped together in a singleembodiment, Figure, or description thereof for the purpose ofstreamlining the disclosure. This method of disclosure, however, is notto be interpreted as reflecting an intention that any claim require morefeatures than those expressly recited in that claim. Rather, as thefollowing claims reflect, inventive aspects lie in a combination offewer than all features of any single foregoing disclosed embodiment.Thus, the claims following this Detailed Description are herebyexpressly incorporated into this Detailed Description, with each claimstanding on its own as a separate embodiment. This disclosure includesall permutations of the independent claims with their dependent claims.

Recitation in the claims of the term “first” with respect to a featureor element does not necessarily imply the existence of a second oradditional such feature or element. Elements recited inmeans-plus-function format are intended to be construed in accordancewith 35 U.S.C. §112 Para. 6. It will be apparent to those having skillin the art that changes may be made to the details of theabove-described embodiments without departing from the underlyingprinciples of the invention.

While specific embodiments and applications of the present inventionhave been illustrated and described, it is to be understood that theinvention is not limited to the precise configuration and componentsdisclosed herein. Various modifications, changes, and variations whichwill be apparent to those skilled in the art may be made in thearrangement, operation, and details of the methods and systems of thepresent invention disclosed herein without departing from the spirit andscope of the invention.

What is claimed is:
 1. An airbag assembly for disposition proximate aroof of a vehicle to shield a vehicle occupant from impacting at leastone lateral surface of the vehicle, the airbag assembly comprising: aninflatable curtain airbag having a stowed configuration proximate theroof of the vehicle and a deployed configuration into which theinflatable curtain airbag deploys downward between the vehicle occupantand the at least one lateral surface of the vehicle, the inflatablecurtain airbag comprising an inboard fabric layer and an outboard fabriclayer that are secured together at a peripheral juncture to define,interior to the peripheral juncture: a first chamber; a second chamberin fluid communication with the first chamber; and a non-inflatingregion extending from the peripheral juncture to at least partiallyseparate the first chamber from the second chamber; wherein thenon-inflating region has a width selected to permit in-plane bending ofthe inflatable curtain airbag in the deployed configuration.
 2. Theairbag assembly of claim 1, wherein the non-inflating region comprises agenerally vertical portion that extends upward from a bottom edge of theperipheral juncture between the first chamber and the second chamber,wherein, in the deployed configuration, the in-plane bending of theinflatable curtain airbag causes the second chamber to be angleddownward relative to the first chamber.
 3. The airbag assembly of claim2, wherein the non-inflating region further comprises a generallyhorizontal portion that extends forward of the generally verticalportion to divide the second chamber into an upper segment and a lowersegment, wherein, in the deployed configuration, the second chamberinflates inboard of a window; and the lower segment extends lower than abottom of the window and lower than the first chamber.
 4. The airbagassembly of claim 3, wherein the second chamber further comprises aforward segment, wherein the upper segment, the forward segment, and thelower segment cooperate to define a single non-branching passageway thatconducts inflation gas from the first chamber to the upper segment, fromthe upper segment to the forward segment, and from the forward segmentto the lower segment.
 5. The airbag assembly of claim 3, wherein, in thedeployed configuration, the lower segment is angled such that on thelower segment, an exterior surface of the inboard fabric layer facesupward.
 6. The airbag assembly of claim 1, wherein the width of thenon-inflating region is between 7 mm and 120 mm.
 7. The airbag assemblyof claim 1, wherein in the deployed configuration, the second chamber ispositioned between an occupant zone that would ordinarily be occupied bythe vehicle occupant's head and at least one of an A-pillar of thevehicle and a portion of an instrument panel of the vehicle.
 8. Theairbag assembly of claim 1, wherein in the deployed configuration, alower portion of the second chamber is in contact with a steering wheelof the vehicle.
 9. The airbag assembly of claim 1, further comprising anattachment feature that attaches a forward portion of the non-inflatingregion to a rearward portion of the non-inflating region such that acompaction feature is defined between the forward portion and therearward portion to compress the width of the non-inflating region,wherein the compaction feature is selected from the group consisting ofa fold and a cut.
 10. The airbag assembly of claim 9, wherein theattachment feature comprises stitching applied to the forward portionand the rearward portion.
 11. A method for manufacturing an airbagassembly for protecting a vehicle occupant from impact against a lateralsurface of the vehicle, the method comprising: providing an inboardfabric layer and an outboard fabric layer; securing the inboard fabriclayer to the outboard fabric layer at a peripheral juncture to form aninflatable airbag curtain; and compacting the inflatable curtain airbaginto a generally elongated shape that facilitates securement of theinflatable curtain airbag proximate a roof of the vehicle such that, inresponse to introduction of inflation gas into the inflatable curtainairbag, the inflatable curtain airbag expands downward into a deployedconfiguration to be positioned between the vehicle occupant and thelateral surface of the vehicle; wherein securing the inboard fabriclayer to the outboard fabric layer comprises defining, interior to theperipheral juncture: a first chamber; a second chamber in fluidcommunication with the first chamber; and a non-inflating regionextending from the peripheral juncture to at least partially separatethe first chamber from the second chamber, wherein the non-inflatingregion comprises a width selected such that, during deployment, theinflatable curtain airbag folds in-plane.
 12. The method of claim 11,wherein defining the non-inflating region comprises forming a generallyvertical portion that extends upward from a bottom edge of theperipheral juncture between the first chamber and the second chamber,wherein the width is further selected such that, in the deployedconfiguration, the in-plane bending of the inflatable curtain airbagcauses the second chamber to be angled downward relative to the firstchamber, the second chamber inflates inboard of a window, and the secondchamber extends significantly lower than a bottom of the window.
 13. Themethod of claim 12, wherein defining the non-inflating region furthercomprises forming a generally horizontal portion that extends forward ofthe generally vertical portion to divide the second chamber into anupper segment, a forward segment, and a lower segment that cooperate todefine a single non-branching passageway that conducts the inflation gasfrom the first chamber to the upper segment, from the upper segment tothe forward segment, and from the forward segment to the lower segment.14. The method of claim 11, wherein compacting the inflatable curtainairbag into the generally elongated shape comprises facilitatingsecurement of the inflatable curtain airbag at a position selected suchthat, in the deployed configuration, the second chamber is positionedbetween an occupant zone that would ordinarily be occupied by thevehicle occupant's head and at least one of an A-pillar of the vehicleand a portion of an instrument panel of the vehicle.
 15. The method ofclaim 11, further comprising attaching a forward portion of thenon-inflating region to a rearward portion of the non-inflating regionwith an attachment feature such that a fold is defined between theforward portion and the rearward portion to compress the width of thenon-inflating region.
 16. The method of claim 15, wherein the attachmentfeature comprises stitching, wherein attaching the forward portion ofthe non-inflating region to the rearward portion of the non-inflatingregion comprises stitching the forward portion to the rearward portion.17. An airbag assembly for disposition proximate a roof of a vehicle toshield a vehicle occupant from impacting at least one lateral surface ofthe vehicle, the airbag assembly comprising: an inflatable curtainairbag having a stowed configuration proximate the roof of the vehicleand a deployed configuration into which the inflatable curtain airbagdeploys downward between the vehicle occupant and the at least onelateral surface of the vehicle, the inflatable curtain airbag comprisingan inboard fabric layer and an outboard fabric layer that are securedtogether at a peripheral juncture to define, interior to the peripheraljuncture: a first chamber; and a second chamber in fluid communicationwith the first chamber, the second chamber comprising a singleunbranching passageway comprising: an upper segment through whichinflation gas enters the second chamber from the first chamber; and alower segment below the upper segment and adjacent to a bottom edge ofthe peripheral juncture, wherein the lower segment directs the inflationgas back toward the first chamber.
 18. The airbag assembly of claim 17,wherein the inboard fabric layer and the outboard fabric layer arefurther secured together to define a non-inflating region comprising agenerally vertical portion that extends upward from a bottom edge of theperipheral juncture to at least partially separate the first chamberfrom the second chamber, and a generally horizontal portion thatseparates the upper segment from the lower segment, wherein the singleunbranching passageway further comprises a forward segment positioned toconvey the inflation gas downward from the upper segment to the lowersegment.
 19. The airbag assembly of claim 17, wherein the inboard fabriclayer and the outboard fabric layer are further secured together todefine a non-inflating region comprising a generally vertical portionthat extends upward from a bottom edge of the peripheral juncture to atleast partially separate the first chamber from the second chamber, anda generally horizontal portion that separates the upper segment from thelower segment, wherein the non-inflating region has a width selected topermit in-plane bending of the inflatable curtain airbag in the deployedconfiguration, wherein the in-plane bending of the inflatable curtainairbag causes the second chamber to be angled downward relative to thefirst chamber such that the second chamber inflates inboard of a window;and the lower segment extends significantly lower than a bottom of thewindow.
 20. The airbag assembly of claim 17, wherein the inboard fabriclayer and the outboard fabric layer are further secured together todefine a non-inflating region comprising a generally vertical portionthat extends upward from a bottom edge of the peripheral juncture to atleast partially separate the first chamber from the second chamber, anda generally horizontal portion that separates the upper segment from thelower segment, the airbag assembly further comprising an attachmentfeature that attaches a forward portion of the non-inflating region to arearward portion of the non-inflating region such that a fold is definedbetween the forward portion and the rearward portion to reduce a widthof the non-inflating region.